Resumo

GARCIA-CASTRO, M. A.; DIAZ-SANCHEZ, F.; GALICIA-AGUILAR, J. A.  e  VIDAL-ROBLES, E.. Standard molar enthalpies of formation of 3-methylglutaric and 3,3-dimethylglutaric anhydrides. Rev. mex. fis. [online]. 2023, vol.69, n.5.  Epub 28-Out-2024. ISSN 0035-001X.  https://doi.org/10.31349/revmexfis.69.051701.

In this research, both the standard molar enthalpy of formation in the crystalline phase and in the gas phase of 3-methylglutaric anhydride was calculated from experimental data. The temperature and enthalpy of fusion, as well as the molar heat capacity in solid phase was calculated by differential scanning calorimetry; the molar enthalpy of sublimation at 298.15 K by the Knudsen effusion method, the molar enthalpy of vaporization at 298.15 K by thermogravimetric analysis, and the standard massic combustion energy by combustion adiabatic calorimetry. Since 3,3-dimethylglutaric anhydride presented crystal transitions (with endothermic points at 352.76 K, 356.98 K and 397.15 K), some of its thermochemical properties were estimated from the functional group-contribution methods proposed by Benson, Gani and Naef and from application of Machine Learning based models.

Palavras-chave : 3-methylglutaric anhydride; 3,3-dimethylglutaric anhydride; enthalpy of formation; functional group-contribution methods.

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